Recruited by the Demons after winning the Toora best and fairest award and representing the Alberton League in a representative game, Osborne played Reserves football for Melbourne while waiting for his clearance to be approved.

Known for being lightning quick, Osborne made his senior 'debut' in a game where he was unused as a reserve. His on-field debut came the next week, and though he was better known as a defender played full forward - the 10th Melbourne player to be tried in that role in the first 12 rounds of 1966.

He represented the VFL Reserves against New South Wales during 1972, and next year was his best with 21 games and 13 goals.

In 1974 he was restricted to seven games by hamstring injuries. In early 1976 the Demons and Hawthorn discussed a clearance to the Hawks that didn't eventuate. Osborne was also linked with WAFL side East Fremantle, and it was claimed that a transfer fee of $7500 had been agreed before Hawthorn became involved in negotiations and Melbourne put the price up to $20k. He had never polled a single Brownlow Medal vote until that season when he scored 18 under the system where both umpires gave votes.

Osborne missed the first five rounds of 1977 with a wrist injury, and played 13 ore games before leaving the Demons. He joined Sandringham in 1978 and played 58 games in four years for the Zebras. Osborne won their best and fairest in 1979 and represented the VFA in 1981. He missed most of 1982 with a knee injury.